The work described here is designed to further our understanding of the structure function assembly, and intracellular movements of proteins that associate with nascent polymerase II transcripts. These proteins play a critical role in the expression of genetic formation. I will study tow different types of proteins; those that interact with most polymerase II transcription units, and those that associate with only one or a few. The specific approaches are: 1) I will express two proteins that interact with most nascent polymerase II transcripts in amphibian oocytes and follow their progression over time as they move to the nucleus, associate with other transcript binding proteins, and interact with the nascent transcripts. To distinguish them from the endogenous forms of these proteins I will use constructs that express thee proteins with an additional 10 amino acids that can be recognized by antibody that does not cross react with any endogenous proteins. 2) I will further characterize a protein that interacts with a specific set of transcription units on chromosome 14 of Xenopus laevis. This phosphoprotein is present widely in the animal kingdom, and is associated with a large novel nuclear substructure.